assume cs:code
code segment
    mov ax, cs
    mov ds, ax
    mov ax, 0020h
    mov es, ax
    mov bx, 00h
    mov cx, 18h ; mov 在寄存器之间传输是 2 字节，寄存器与立即数之间是 3 字节
    s:
        mov al, [bx]
        mov es:[bx], al
        inc bx
        loop s
    mov ax, 4c00h
    int 21h
code ends
end